body {
  padding: 20px;
}

.container {
  margin: 20px auto;
  max-width: 500px;
  padding: 30px 20px;
  background-color: #eee;
  box-shadow: 0 5px 5px #aaa;
  border-radius: 10px;
}

h1 {
  text-align: center;
}

label {
  font-weight: bold;
}

form>input, textarea, select {
  width: 100%;
  margin-top: 10px;
  margin-bottom: 15px;
  border: 1px solid #666;
  border-radius: 5px;
}

input, select {
  height: 1.5rem;
}

.radio-group {
  text-align: center;
}

.radio-group input {
  width: 10px;
  height: 10px;
}

.radio-group legend {
  font-weight: bold;
  text-align: left;
}

.radio-group label {
  text-align: left;
  font-weight: normal;
  margin: 10px;
}

input:focus, textarea:focus {
  border-color: blue;
}

input:invalid, select:invalid, textarea:invalid {
  border-color: red;
}

input:valid, select:valid, textarea:valid {
  border-color: green;
}

button:hover {
  background-color: skyblue;
}

.radio-group input[type="radio"]:checked {
  border-color: green;
  background-color: orange;
  box-shadow: 0 5px 5px gray;
}

input:first-of-type {
  border-radius: 5px;
}

button {
  display: block;
  margin: 10px auto;
  width: 100%;
  padding: 10px;
  background-color: green;
  color: white;
  font-size: 1.2rem;
}

input[type="radio"]:checked+label {
    color: green;
}